1. Field of the Invention
This invention relates generally to devices for drug reconstitution and especially to the inputting structure for effecting the desired procedure.
2. Description of the Prior Art
A common problem of known devices for drug reconstitution is that the devices known and being used today utilize two basic concepts. According to one concept, devices having plastic spikes with separate holes for fluid and air are employed. However, such devices cannot be made small enough in diameter to prevent damage to small 13 millimeter rubber stoppers with which it would be desirable to use same. In a second concept, hypodermic needles having a vent sleeve around the needle have been used. This design will easily puncture the smaller stoppers, but because the vent sleeve itself is shorter than the needle for the fluid path, air will be sucked into the fluid path during the aspiration process. This is obviously undesirable.
Existing prior patents which may be pertinent to the present invention are as follows:
______________________________________ 2,409,343 10/15/46 3,662,752 5/16/72 4,505,709 3/19/85 4,507,113 3/26/85 4,534,758 8/13/85 4,610,683 9/9/86 ______________________________________
In the Curtis U.S. Pat. No. 2,409,343, an arrangement is disclosed wherein the large cannula is utilized for the air passageway, and the smaller cannula associated therewith is utilized to facilitate aspiration of the liquid contents from a bottle. However, this device has parallel tubes which are closely contiguous as compared to the present invention having concentric tubes that do not touch. In the Curtis device, it is also disclosed that the tubes can be interchanged with each other. In the present invention, the liquid and air channels are separate, are fixed in place, and cannot be interchanged. Furthermore, in the Curtis device, each tube has an open end for the attachment of tubing; while in the present invention, molded fittings specifically for the purpose of attachment of a syringe and hydrophobic filter are provided.
The other patents listed have various arrangements involving cannulas or spikes and associated air passageways. However, none of the known prior art devices offer the new and novel features of the present invention.